[NFC][AArch64] Get default features directly from ArchInfo and CpuInfo objects

[pratlucas]

Summary

This updates the AArch64's Target Parser and its uses to capture
information about default features directly from ArchInfo and CpuInfo
objects, instead of relying on an API function to access them
indirectly.

[tmatheson]

Looks great, thanks

llvm/include/llvm/TargetParser/AArch64TargetParser.h

338

nit: I would expect getDefaultExtensions() to return the value of DefaultExtensions. Is there a better naming combo we could use?

[pratlucas]

Renaming getDefaultExtensions() to getImpliedExtensions().

clang/lib/Basic/Targets/AArch64.cpp

void AArch64TargetInfo::setFeatureEnabled(llvm::StringMap<bool> &Features,
   if (!ArchInfo)
     return; // Not an architecure, nothing more to do.
 
   for (const auto *OtherArch : llvm::AArch64::ArchInfos)
     if (ArchInfo->implies(*OtherArch))
       Features[OtherArch->getSubArch()] = Enabled;
 
   // Set any features implied by the architecture
-  uint64_t Extensions =
-      llvm::AArch64::getDefaultExtensions("generic", *ArchInfo);
   std::vector<StringRef> CPUFeats;
-  if (llvm::AArch64::getExtensionFeatures(Extensions, CPUFeats)) {
+  if (llvm::AArch64::getExtensionFeatures(ArchInfo->DefaultExts, CPUFeats)) {
     for (auto F : CPUFeats) {
       assert(F[0] == '+' && "Expected + in target feature!");
       Features[F.drop_front(1)] = true;
     }
   }
 }
 
 bool AArch64TargetInfo::handleTargetFeatures(std::vector<std::string> &Features,

 
 bool AArch64TargetInfo::initFeatureMap(
     llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags, StringRef CPU,
     const std::vector<std::string> &FeaturesVec) const {
   std::vector<std::string> UpdatedFeaturesVec;
   // Parse the CPU and add any implied features.
   std::optional<llvm::AArch64::CpuInfo> CpuInfo = llvm::AArch64::parseCpu(CPU);
   if (CpuInfo) {
-    uint64_t Exts = llvm::AArch64::getDefaultExtensions(CPU, CpuInfo->Arch);
+    uint64_t Exts = CpuInfo->getImpliedExtensions();
     std::vector<StringRef> CPUFeats;
     llvm::AArch64::getExtensionFeatures(Exts, CPUFeats);
     for (auto F : CPUFeats) {
       assert((F[0] == '+' || F[0] == '-') && "Expected +/- in target feature!");
       UpdatedFeaturesVec.push_back(F.str());
     }
   }
 

clang/lib/Driver/ToolChains/Arch/AArch64.cpp

if (CPU == "generic") {
     const std::optional<llvm::AArch64::CpuInfo> CpuInfo =
         llvm::AArch64::parseCpu(CPU);
     if (!CpuInfo)
       return false;
     ArchInfo = &CpuInfo->Arch;
 
     Features.push_back(ArchInfo->ArchFeature);
 
-    uint64_t Extension = llvm::AArch64::getDefaultExtensions(CPU, *ArchInfo);
+    uint64_t Extension = CpuInfo->getImpliedExtensions();
     if (!llvm::AArch64::getExtensionFeatures(Extension, Features))
       return false;
   }
 
   if (Split.second.size() &&
       !DecodeAArch64Features(D, Split.second, Features, *ArchInfo))
     return false;
 

llvm/include/llvm/TargetParser/AArch64TargetParser.h

 };
 
 // Details of a specific CPU.
 struct CpuInfo {
   StringRef Name; // Name, as written for -mcpu.
   const ArchInfo &Arch;
   uint64_t DefaultExtensions; // Default extensions for this CPU. These will be
                               // ORd with the architecture defaults.
+
+  uint64_t getImpliedExtensions() const {
+    return DefaultExtensions | Arch.DefaultExts;
+  }
 };
 
 inline constexpr CpuInfo CpuInfos[] = {
     {"cortex-a34", ARMV8A, (AArch64::AEK_CRYPTO | AArch64::AEK_CRC)},
     {"cortex-a35", ARMV8A, (AArch64::AEK_CRYPTO | AArch64::AEK_CRC)},
     {"cortex-a53", ARMV8A, (AArch64::AEK_CRYPTO | AArch64::AEK_CRC)},
     {"cortex-a55", ARMV8_2A,
      (AArch64::AEK_CRYPTO | AArch64::AEK_FP16 | AArch64::AEK_DOTPROD |

 
 bool getExtensionFeatures(uint64_t Extensions,
                           std::vector<StringRef> &Features);
 
 StringRef getArchExtFeature(StringRef ArchExt);
 StringRef resolveCPUAlias(StringRef CPU);
 
 // Information by Name
-uint64_t getDefaultExtensions(StringRef CPU, const ArchInfo &AI);
 void getFeatureOption(StringRef Name, std::string &Feature);
 std::optional<ArchInfo> getArchForCpu(StringRef CPU);
 
 // Parser
 std::optional<ArchInfo> parseArch(StringRef Arch);
 std::optional<ExtensionInfo> parseArchExtension(StringRef Extension);
 // Given the name of a CPU or alias, return the correponding CpuInfo.
 std::optional<CpuInfo> parseCpu(StringRef Name);

llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp

if (!ArchInfo)
     return Error(ArchLoc, "unknown arch name");
 
   if (parseToken(AsmToken::EndOfStatement))
     return true;
 
   // Get the architecture and extension features.
   std::vector<StringRef> AArch64Features;
   AArch64Features.push_back(ArchInfo->ArchFeature);
-  AArch64::getExtensionFeatures(
-      AArch64::getDefaultExtensions("generic", *ArchInfo), AArch64Features);
+  AArch64::getExtensionFeatures(ArchInfo->DefaultExts, AArch64Features);
 
   MCSubtargetInfo &STI = copySTI();
   std::vector<std::string> ArchFeatures(AArch64Features.begin(), AArch64Features.end());
   STI.setDefaultFeatures("generic", /*TuneCPU*/ "generic",
                          join(ArchFeatures.begin(), ArchFeatures.end(), ","));
 
   SmallVector<StringRef, 4> RequestedExtensions;
   if (!ExtensionString.empty())

llvm/lib/TargetParser/AArch64TargetParser.cpp

 using namespace llvm;
 
 static unsigned checkArchVersion(llvm::StringRef Arch) {
   if (Arch.size() >= 2 && Arch[0] == 'v' && std::isdigit(Arch[1]))
     return (Arch[1] - 48);
   return 0;
 }
 
-uint64_t AArch64::getDefaultExtensions(StringRef CPU,
-                                       const AArch64::ArchInfo &AI) {
-  if (CPU == "generic")
-    return AI.DefaultExts;
-
-  // Note: this now takes cpu aliases into account
-  std::optional<CpuInfo> Cpu = parseCpu(CPU);
-  if (!Cpu)
-    return AI.DefaultExts;
-
-  return Cpu->Arch.DefaultExts | Cpu->DefaultExtensions;
-}
-
 void AArch64::getFeatureOption(StringRef Name, std::string &Feature) {
   for (const auto &E : llvm::AArch64::Extensions) {
     if (Name == E.Name) {
       Feature = E.Feature;
       return;
     }
   }
   Feature = Name.str();

llvm/unittests/TargetParser/TargetParserTest.cpp

 
 TEST_P(AArch64CPUTestFixture, testAArch64CPU) {
   ARMCPUTestParams params = GetParam();
 
   const std::optional<AArch64::CpuInfo> Cpu = AArch64::parseCpu(params.CPUName);
   EXPECT_TRUE(Cpu);
   EXPECT_EQ(params.ExpectedArch, Cpu->Arch.Name);
 
-  uint64_t default_extensions =
-      AArch64::getDefaultExtensions(params.CPUName, Cpu->Arch);
   EXPECT_PRED_FORMAT2(
       AssertSameExtensionFlags<ARM::ISAKind::AARCH64>(params.CPUName),
-      params.ExpectedFlags, default_extensions);
+      params.ExpectedFlags, Cpu->getImpliedExtensions());
 }
 
 INSTANTIATE_TEST_SUITE_P(
     AArch64CPUTests, AArch64CPUTestFixture,
     ::testing::Values(
         ARMCPUTestParams("cortex-a34", "armv8-a", "crypto-neon-fp-armv8",
                          AArch64::AEK_CRC | AArch64::AEK_CRYPTO |
                              AArch64::AEK_FP | AArch64::AEK_SIMD,

 }
 
 bool testAArch64Extension(StringRef CPUName, StringRef ArchExt) {
   std::optional<AArch64::ExtensionInfo> Extension =
       AArch64::parseArchExtension(ArchExt);
   if (!Extension)
     return false;
   std::optional<AArch64::CpuInfo> CpuInfo = AArch64::parseCpu(CPUName);
-  return (CpuInfo->Arch.DefaultExts | CpuInfo->DefaultExtensions) & Extension->ID;
+  return CpuInfo->getImpliedExtensions() & Extension->ID;
 }
 
 bool testAArch64Extension(const AArch64::ArchInfo &AI, StringRef ArchExt) {
   std::optional<AArch64::ExtensionInfo> Extension =
       AArch64::parseArchExtension(ArchExt);
   if (!Extension)
     return false;
   return AI.DefaultExts & Extension->ID;